Browsing by Author "Marques, Alexandra P."
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- Finely tuned fiber-based porous structures for bone tissue engineering applicationsPublication . Ribeiro, Viviana; Silva-Correia, Joana; Morais, Alain; Correlo, Vitor M.; Marques, Alexandra P.; Ribeiro, Ana; Silva, Carla; Durães, Nelson; Bonifácio, Graça; Sousa, Rui A.; Oliveira, Joaquim M.; Oliveira, Ana L.; Reis, Rui L.
- Influence of different surface modification treatments on silk biotextiles for tissue engineering applicationsPublication . Ribeiro, Viviana P.; Almeida, Lília R.; Martins, Ana R.; Pashkuleva, Iva; Marques, Alexandra P.; Ribeiro, Ana S.; Silva, Carla J.; Bonifácio, Graça; Sousa, Rui A.; Reis, Rui L.; Oliveira, Ana L.Biotextile structures from silk fibroin have demonstrated to be particularly interesting for tissue engineering (TE) applications due to their high mechanical strength, interconnectivity, porosity, and ability to degrade under physiological conditions. In this work, we described several surface treatments of knitted silk fibroin (SF) scaffolds, namely sodium hydroxide (NaOH) solution, ultraviolet radiation exposure in an ozone atmosphere (UV/O3) and oxygen (O2) plasma treatment followed by acrylic acid (AAc), vinyl phosphonic acid (VPA), and vinyl sulfonic acid (VSA) immersion. The effect of these treatments on the mechanical properties of the textile constructs was evaluated by tensile tests in dry and hydrated states. Surface properties such as morphology, topography, wettability and elemental composition were also affected by the applied treatments. The in vitro biological behavior of L929 fibroblasts revealed that cells were able to adhere and spread both on the untreated and surface-modified textile constructs. The applied treatments had different effects on the scaffolds' surface properties, confirming that these modifications can be considered as useful techniques to modulate the surface of biomaterials according to the targeted application.
- Modulating cell adhesion to polybutylene succinate biotextile constructs for tissue engineering applicationsPublication . Ribeiro, Viviana P.; Almeida, Lília R.; Martins, Ana R.; Pashkuleva, Iva; Marques, Alexandra P.; Ribeiro, Ana S.; Silva, Carla J.; Bonifácio, Graça; Sousa, Rui A.; Oliveira, Ana L.; Reis, Rui L.Textile-based technologies are powerful routes for the production of three-dimensional porous architectures for tissue engineering applications because of their feasibility and possibility for scaling-up. Herein, the use of knitting technology to produce polybutylene succinate fibre-based porous architectures is described. Furthermore, different treatments have been applied to functionalize the surface of the scaffolds developed: sodium hydroxide etching, ultraviolet radiation exposure in an ozone atmosphere and grafting (acrylic acid, vinyl phosphonic acid and vinyl sulphonic acid) after oxygen plasma activation as a way to tailor cell adhesion. A possible effect of the applied treatments on the bulk properties of the textile scaffolds has been considered and thus tensile tests in dry and hydrated states were also carried out. The microscopy results indicated that the surface morphology and roughness were affected by the applied treatments. The X-ray photoelectron spectroscopy and contact angle measurements showed the incorporation of oxygen-containing groups and higher surface free energy as result of the surface treatments applied. The DNA quantification and scanning electron microscopy analysis revealed that these modifications enhanced cell adhesion and altered cell morphology. Generally, sodium hydroxide treatment altered most significantly the surface properties, which in turn resulted in a high number of cells adherent to these surfaces. Based on the results obtained, the proposed surface treatments are appropriate to modify polybutylene succinate knitting scaffolds, influencing cell adhesion and its potential for use in tissue engineering applications.
- Silk-based anisotropical 3D biotextiles for bone regenerationPublication . Ribeiro, Viviana P.; Silva-Correia, Joana; Nascimento, Ana I.; Morais, Alain da Silva; Marques, Alexandra P.; Ribeiro, Ana S.; Silva, Carla J.; Bonifácio, Grata; Sousa, Rui A.; Oliveira, Joaquim M.; Oliveira, Ana L.; Reis, Rui L.Bone loss in the craniofacial complex can been treated using several conventional therapeutic strategies that face many obstacles and limitations. In this work, novel three-dimensional (3D) biotextile architectures were developed as a possible strategy for flat bone regeneration applications. As a fully automated processing route, this strategy as potential to be easily industrialized. Silk fibroin (SF) yarns were processed into weft-knitted fabrics spaced by a monofilament of polyethylene terephthalate (PET). A comparative study with a similar 3D structure made entirely of PET was established. Highly porous scaffolds with homogeneous pore distribution were observed using micro-computed tomography analysis. The wet state dynamic mechanical analysis revealed a storage modulus In the frequency range tested, the storage modulus values obtained for SF-PET scaffolds were higher than for the PET scaffolds. Human adipose-derived stem cells (hASCs) cultured on the SF-PET spacer structures showed the typical pattern for ALP activity under osteogenic culture conditions. Osteogenic differentiation of hASCs on SF PET and PET constructs was also observed by extracellular matrix mineralization and expression of osteogenic-related markers (osteocalcin, osteopontin and collagen type I) after 28 days of osteogenic culture, in comparison to the control basal medium. The quantification of convergent macroscopic blood vessels toward the scaffolds by a chick chorioallantoic membrane assay, showed higher angiogenic response induced by the SF-PET textile scaffolds than PET structures and gelatin sponge controls. Subcutaneous implantation in CD-1 mice revealed tissue ingrowth's accompanied by blood vessels infiltration in both spacer constructs. The structural adaptability of textile structures combined to the structural similarities of the 3D knitted spacer fabrics to craniofacial bone tissue and achieved biological performance, make these scaffolds a possible solution for tissue engineering approaches in this area.
- Textile-based silk scaffolds for bone tissue engineering applicationsPublication . Ribeiro, Viviana; Morais, Alain; Correlo, Vitor M.; Marques, Alexandra P.; Ribeiro, Ana; Silva, Carla; Durães, Nuno; Bonifácio, Graça; Sousa, Rui; Oliveira, Joaquim M.; Reis, Rui L.; Oliveira, Ana L.INTRODUCTION: Scaffolds developed for bone tissue engineering (TE) need to facilitate and promote cell adhesion, proliferation and neo-tissue formation. They must possess specific properties to allow the new tissue to integrate with the material, without inducing any inflammatory response. The intra-architectural scaffold geometry, porosity, scaffold material and surface area play important roles in this process . Several polymeric systems (natural and/or synthetic) and processing methods and have been proposed to develop the “ideal” scaffold for bone TE. However, so far the proposed strategies do not fulfil all the requirements for effective bone regeneration. Textile-based technologies constitute an innovative alternative for the production of 3D structures for bone TE applications, offering a superior control over scaffolds’ design, manufacturing and reproducibility. Silk fibroin (SF) derived from silkworm Bombyx mori has already proved to be a good biomaterial for bone TE applications. SF-based structures offer impressive mechanical properties, biodegradability, biocompatibility and stability, which meets the basic requirements for the design of structures for bone regeneration applications. EXPERIMENTAL METHODS: In this work we describe for the first time the processing of natural silk yarns into 3D scaffolds, combining standard knitting fabrics spaced by a monofilament of polyethylene terephthalate (PET). A comparative study is established using a stable polymeric system made entirely of PET. The obtained knitted spacer constructs were described in terms of morphology and mechanical properties. An in vitro biological assay was performed to evaluate the potential of the developed structures to support human Adipose- derived Stem Cells (hASCs) adhesion, proliferation and osteogenic differentiation. Cells were cultured over 28 days in standard basal and osteogenic conditions and evaluated through different quantitative (DNA, ALP, Calcium, RT-PCR) and qualitative (SEM, Alizarin Red, immunocytochemistry) assays. The in vivo biocompatibility of the textile materials was assessed by subcutaneous implantation in mice model. After 2 and 4weeks of implantation the explants were collected and the obtained slides were stained with hematoxylin and eosin (H&E). RESULTS AND DISCUSSION: The cross-sections of the developed spacer textile constructs reveal a significant increase of the scaffolds three-dimensionality induced by the PET monofilament (Figure 1a). The hASCs seeded onto the spacer textile scaffolds were able to attach, spread, proliferate and differentiate, both in osteogenic and basal conditions (Figure 1b). Great evidences of ECM mineralization were observed, also penetrating and colonizing the PET monofilament (Figure 1a). The preliminary in vivo results revealed that the implanted scaffolds allowed tissue ingrowth, without inducing any acute inflammatory reaction (Figure 1c). CONCLUSION: In this study, innovative 3D biotextile scaffolds able to support cell adhesion, proliferation and osteogenesis were successfully developed. Furthermore, these scaffolds allowed the new tissue formation and integration within the material, when subcutaneously implanted in mice. Thus, the proposed textile-based scaffolds can be promising candidates for bone TE applications such as the craniomaxilofacial complex.